Make the resolver implementation configurable via a new template resolver.gotpl

[penard-cb]

Describe your PR and link to any relevant issues.

I'm adding the ability to pass in a new ResolverTemplate to the ResolverConfig which allows the user to configure a new layout and custom template to generate resolvers.

I made #2724 and this PR should fix it.

What happened?

I need to be able to run gqlgen and pass in a template for generating a resolver.

I need to be able to pass in new imports and make significant code additions (maybe even some convenience methods). This will allow my implementing team to follow my guidlines.

What did you expect?

I thought the config would have an option to just replace the whole gotpl file... it doesn't.

Minimal graphql.schema and models to reproduce

type Query {
    resolver: Resolver!
}

type Resolver {
    name: String!
}

schema:
  - "testdata/schema.graphql"

exec:
  filename: testdata/singlefile/out/ignored.go
model:
  filename: testdata/singlefile/out/generated.go
resolver:
  type: CustomResolverType
  layout: follow-schema
  dir: testdata/resolvertemplate/out
  filename_template: "{name}.resolvers.go"
  resolver_template: "testdata/resolvertemplate/customResolverTemplate.gotpl"

models:
  Resolver:
    model: github.com/99designs/gqlgen/plugin/resolvergen/testdata/singlefile/out.Resolver

I have:

• Added tests covering the bug / feature (see testing)
• Updated any relevant documentation (see docs)

[StevenACoffman]

Cool! I'm looking forward to seeing where this goes. Thanks for working on it!

[penard-cb]

Cool! I'm looking forward to seeing where this goes. Thanks for working on it!

@StevenACoffman I just pushed an update. I also joined the discord, let me know if you want to chat about it. I think this is ready for review.

[dmaulick]

+1 looking forward to this change

[StevenACoffman]

@penard-cb I noticed there are some test failures. If you could take a look, I would appreciate it.
It's possible you just need to regenerate some files or run the go mod tidy:

go generate ./...; cd _examples; go generate ./...

act --artifact-server-path /tmp/artifacts -j test -W .github/workflows/test.yml

[penard-cb]

@StevenACoffman Thanks. I was able to run those commands locally and think I found the issue. I pushed up an update. 🤞

[coveralls]

coverage: 75.734% (-0.004%) from 75.738% when pulling cb384d3 on penard-cb:custom-resolver-templates into cccc738 on 99designs:master.

[tsingsun]

may helpless if not support customer function in template.

[penard-cb]

@tsingsun What do you mean? You can modify the template as you see fit.

[tsingsun]

i mean that how to pass the custom function to the template, like use template.Func.
user custom templates, most likely not just for formatting.

[penard-cb]

Hi @tsingsun . Ah I see. Yes, I have a couple of branches where I'm thinking through how to do that. Requires some interesting and substantial refactor though. I will likely continue working on it within the next month. Happy to collaborate if you have some ideas.